Legend:

I have running Debian and CentOS on my VirtualBox (MacBook, 32-bit, MacOS 10.5), both 32-bit and 64-bit versions, and noticed that ntpd works fine on 32-bit guests and fails to find time sources on 64-bit. Probably it happens on all Linux systems. Example of ntpd debug output (CentOS x86_64):

I have running Debian and CentOS on my VirtualBox (MacBook, 32-bit, MacOS 10.5), both 32-bit and 64-bit versions, and noticed that ntpd works fine on 32-bit guests and fails to find time sources on 64-bit. Probably it happens on all Linux systems.